Three senior Bush administration officials left for the Middle East Monday for more talks on Israeli Prime Minister Ariel Sharon's plans for "disengagement" from the Palestinians starting with removal of Israeli settlements from Gaza. The mission precedes U.S. visits in April by Mr. Sharon, Egyptian President Hosni Mubarak and Jordan's King Abdullah.

It is the third trip to the region since mid-February by the American team, reflecting intense U.S. interest in the Sharon plan, and in whether or not it can advance the Bush administration's vision of a two-state solution to the Israeli-Palestinian conflict through the international peace "road map."

Mr. Sharon has proposed the removal of almost all settlements from the Gaza strip as a first phase of a "disengagement" strategy that also involves the removal of some of the more remote Israeli settlements in the West Bank, coupled with completion of the controversial Israeli security barrier in that region.

Israel says it will act unilaterally in the absence of a Palestinian negotiating partner, and that the Sharon plan provides a so-called "parking place" that would reduce Israeli-Palestinian contact and friction until full scale pace talks can resume.

The U.S. team of Deputy White House National Security Adviser Stephen Hadley, White House Middle East policy director Elliot Abrams and Assistant Secretary of State William Burns will hold talks with the European Union in Brussels before going on to Jerusalem for expected meetings with Israeli and Palestinian officials.

Announcing their departure at a news briefing, State Department spokesman Richard Boucher said the process under way is a not a negotiation over the plan, but a dialogue on whether it can help move the parties closer to peace.

"They're discussing, fundamentally, the president's vision, how to achieve it, and how the various steps discussed by Israel, or are being taken in the region, can contribute to that achievement. As we've made clear before, there's a back-and-forth process here," he said. "We are asking questions, looking for answers on a lot of questions we've had. And there's been an ongoing dialogue between us and the Israeli government but also between us and other regional players as to how these steps, or other steps, can be taken to further proceed down the path outlined by the president of two states living side-by-side in peace."

Mr. Boucher downplayed the notion that Mr. Sharon's domestic problems, including a possible bribery indictment against him, would affect the dialogue. He said the visit of the U.S. policy trio was, as always, approved by Israeli administration and that they intend "to go out and pursue our agenda."

Mr. Sharon will pay a critical visit to the White House April 14th to discuss his plans with President Bush.

That will follow by two days a Crawford, Texas meeting between Mr. Bush and Egyptian President Hosni Mubarak. Jordan's King Abdullah is to round out the top-level diplomacy with a White House visit April 21.

In another development, the State Department said the Bush administration had hoped that the Arab League Summit in Tunis, a critical session on, among other things regional political reform, could have gone forward.

But Mr. Boucher said the summit postponement "doesn't change in the least" the U.S. commitment to supporting home-grown reform and modernization in the Middle East.

He said the United States still plans to present its reform plan, the Greater Middle East Initiative, at the G-8 summit of industrialized countries in the U.S. state of Georgia in June.